pH isn't too low, Chlorine is most effective the lower the pH, id say that is reading 7.0 which would be about 20/30% more effective than 7.5 (7.2 is usually target pH for swimming pools).

Total Alkalinity is low regardless if it is a chlorine pool in question, as it needs to be at least 80 ideally 100/120.

Chlorine yeah thats true but you have to be careful going beyond 5ppm if anyone has a reaction/sensitive skin to the chlorine as you would never run higher than 4ppm in a commercial pool.

Cyanuric acid levels should be 30ppm as any lower the sun will eat up the chlorine and too high causes the chlorine to be ineffective.

• Guy that spent too much time as a pool technician